The present invention relates to container closures, and more particularly to squeeze-type container dispensing closures.
There are two major trends occurring in the design of dispensing containers and closures. The first trend is a focus on providing a “clean pour” during dispensing of the product. Many food products, such as mustard and ketchup, have a high viscosity and require the user to tip the container, shake down the product and then squeeze the container to dispense the product. Past dispensing closures tended to leak product onto the top deck of the closure after dispensing, creating a messy appearance and often requiring cleaning to reseal the closure. The current emphasis in “clean pour” design is on preventing spurting of the product when the container is inverted to the dispensing position and/or shaken down, and creating a “suck-back” effect as pressure is released from the container to draw the product back into the closure.
A second trend is a growing number of dispensing containers and closures being designed so that they can be stored in an inverted position, i.e. cap down. In this regard, the product is always located right at the dispensing closure for easy dispensing right from storage. This reduces the need to tip and shake the container to push the product down to the dispensing closure. There is a balance however, between having the product at the closure for dispensing and the need to prevent the product from immediately spurting out once the lid of the closure is opened.
Both of these trends have resulted in the design of dispensing closures having various types of valve structures that facilitate both a clean pour and inverted storage. For example, a silicone valve structure is illustrated and described in U.S. Pat. No. 5,271,531. While these silicone valves have been widely accepted by both the manufacturers and the consumers, they are somewhat more difficult to manufacture, as they require several inter-fitting parts, and thus they tend to be more expensive than traditional one-piece dispensing closures.
Another perceived drawback to the silicone valve closure is that they are constructed out of two different types of plastic and thus, from a recycling standpoint, they are more difficult to recycle because the silicone valve must be separated from the plastic closure body for recycling. While this is not a major issue in the United States, at least yet, it is currently a major issue in Europe where recycling is extremely important and even mandated in some countries.
Other designs of dispensing closures focus on the use of interior partitions to slow the flow of the product exiting the dispensing orifice. For example, U.S. Pat. No. 5,123,575 discloses a design of a dispensing closure having multiple chambers. This patent discloses a container for motor oil with three interior chambers, namely a primary chamber between the first partition and the bottom wall, a secondary partition between the first and second partitions and a tertiary chamber between the top wall and the second partition. While the concept of the design may provide the desired flow characteristics, the design is virtually impossible to mold using conventional injection molding or blow molding techniques and thus is not commercially feasible.
U.S. Pat. No. 5,819,994 also discloses a dispensing closure using multiple chambers. This patent discloses a flow controlling cap for a fluid (water) container that controls fluid flow by means of gravity and pressure, and has a first chamber formed by a first hollow cylinder and a second chamber formed by a second hollow cylinder having a greater diameter than the first hollow cylinder. While the circuitous path of this design is effective for water, the flow characteristics of water are different than other viscous fluids and thus the design is not believed to be suited for other more viscous products. In short, it would be difficult to force viscous fluids through the multi-chamber design.
Accordingly, there exists a need in the industry for a one-piece dispensing closure that provides a “clean pour” and prevents premature flowing of viscous product prior to squeezing the dispensing container. In addition, there exists a need a design of a dispensing closure that is easy to mold and made of one type of recyclable plastic.